How to Remove Oracle Java JDK 7 Ubuntu 15.04 14.10 14.04 13.04 12.04

1)
Check which JDK packages are installed
#sudo dpkg --list | grep -i jdk

2)
Remove Oracle Java 7
#sudo apt-get purge oracle-java7-installer
OR
#sudo apt-get remove oracle-java7-installer

3)
Check that all JDK packages have been removed
#sudo dpkg --list | grep -i jdk